4.Umami

Our tongues can detect five different tastes. You know four of them: salt, sweet, bitter, and sour. But the fifth, "umami", is more obscure. It's the meaty, savoury taste that makes things like Marmite and gravy so moreish – more scientifically, it's the taste of a chemical group called glutamates. The word comes from the Japanese for "deliciousness".

8.Lucubration

Pocket Books

The product of laborious study. The implication, usually, is that the person whose lucubration it is has indeed worked long and hard through the night – but it's still not very good. From lucubrare, Latin for "to work by lamplight".

12.Nesh

An adjective meaning "more than usually susceptible to the cold". An English dialect term found in Lancashire, South Yorkshire, Staffordshire, the East Midlands, and Shropshire. If you really hate the winter, this might be the word for you.

13.Eisenbahnscheinbewegung

A word invented by Ben Schott, which means "the false sensation of movement when, looking out from a stationary train, you see another train depart". Has yet to make it into any dictionaries, since probably no actual human being has ever used the word, but it should do.

18.Hiraeth

A Welsh word with no direct English translation that means something like: "A homesickness for a home to which you cannot return, a home which maybe never was; the nostalgia, the yearning, the grief for the lost places of your past." One imagines Tom Jones feeling this for the valleys while sipping champagne in his LA mansion. Related to the Portuguese concept of saudade.

20.Persiflage

Taken from "Oscar Wilde, Volume 1 (of 2): His Life and Confessions" by Frank Harris. Public domain / Via en.wikipedia.org

Frivolous, light-hearted talk. A useful word, because it makes you sound like Oscar Wilde and lets you avoid ever describing your witty repartée as "banter".

21.Palimpsest

The Codex Ephraemi Rescriptus, a Greek palimpsest from the 5th century. Public domain / Via en.wikipedia.org

An old document which has had the original writing scraped off so that new words can be written over it. Now usually used in a metaphorical sense: The geological record is a palimpsest of the ages of the Earth; someone's face is a palimpsest revealing the pains of their life. From the Greek palimpsēstos, "scraped again".

23.Chthonic

24.Panglossian

Frontispiece and first page of chapter one of an early English translation by T. Smollett et al of Voltaire's Candide, printed by John Newbery, 1762. Public domain / Via en.wikipedia.org

"Characterised by or given to extreme optimism, especially in the face of unrelieved hardship or adversity." Like the guy singing "Always look on the bright side of life" as he's getting crucified at the end of Monty Python's Life of Brian.

From Dr Pangloss, a character in Voltaire's Candide and a parody of the German philosopher Gottfried Leibniz, who claimed that this is the best of all possible worlds.

27.Prolix

28.Hygge

Getty Images/iStockphoto Elenathewise

This is a Danish word with no direct translation, but it seems to mean something like that feeling when there are a few of you in a room playing board games at Christmas, and it's freezing cold outside and you can hear the drumming of bitter rain on the window, but it's warm and cosy in the room and there's an open fire roaring and you have mulled wine and biscuits and everyone's having a good time. It's a sort of combination of cosiness and companionship and happiness and warmth, and it would be a lovely word to get into English.

29.Dunandunate

Getty Images/iStockphoto Vladimir Nikulin

A word that, sadly, has not made it into the Oxford English Dictionary, but is relevant here: It is a verb meaning "to overuse a word or phrase that has been recently added to one's vocabulary", or "to learn a word and then use it incessantly".